Tissue specific transcriptional regulatory elements have been identified which have been used to target expression of exogenous genes in cells and in transgenic animals. For example, DNA constructs using an erythroid specific transcriptional element and an oncogene encoding a protein having protein-tyrosine kinase (PTK) activity have been used to produce transgenic animals which have cardiovascular disease (Yee, S.P. et al. (1989) P.N.A.S., U.S.A. 86, 5873-5877).
The ability to introduce into animals exogenous genes which are selectively expressed in a particular cell type provides wide ranging experimental as well as practical opportunities. In particular it permits investigation of the role of a substance in the development, determination, migration, or proliferation of cells of a particular lineage.